Drawing on new institutionalism theory, this study examines the influence of institutional logics, the belief systems that direct decision-makers’ attention to particular sets of issues, on human resource (HR) adaptation to demographic changes. We argue that the prevalence of age-neutral HR management and of age-related HR practices such as age assessment and older worker-targeted practices, are shaped by the strength of the strategic (business case), benchmarking (comparing one’s set of policies with peers’) and compliance (laws and regulations) logics. In a sample of 420 US organizations, a strong strategic logic was associated only with greater prevalence of age-neutral HR management. A strong benchmarking logic was associated with greater prevalence of age-neutral HR management, of age assessment practices, and of older worker-targeted practices. A strong compliance logic was associated with greater prevalence of age-assessment and older worker-targeted practices. This article contributes to research on ageing and extends work on institutional logics by (1) focusing on organizations’ differential enactment of institutional logics, reflecting the contextual embeddedness of HR practices, and (2) showing that the prevalence of age-neutral HR management and of age-related HR practices are associated with competitive as well as institutional isomorphism.